<!doctype html>
<title>Highlight is a setlike interface that works as expected even if Set.prototype is tampered</title>
<link rel="help" href="https://drafts.csswg.org/css-highlight-api-1/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
"use strict";
function tamperSetPrototype() {
delete Set.prototype.size;
Set.prototype.entries = null;
Set.prototype.forEach = undefined;
Set.prototype.has = "foo";
Set.prototype.keys = 0;
Set.prototype.values = Symbol();
Set.prototype[Symbol.iterator] = 1;
Set.prototype.add = true;
Set.prototype.clear = "";
Set.prototype.delete = -1.5;
Object.freeze(Set.prototype);
}
test(() => {
tamperSetPrototype();
const staticRange = new StaticRange({startContainer: document.body, endContainer: document.body, startOffset: 0, endOffset: 0});
const highlight = new Highlight(staticRange);
assert_equals(highlight.size, 1);
assert_true(highlight.has(staticRange));
assert_equals([...highlight.entries()][0][0], staticRange);
highlight.clear();
assert_equals(highlight.size, 0);
highlight.add(staticRange);
assert_equals(highlight.size, 1);
highlight.delete(staticRange);
assert_equals(highlight.size, 0);
assert_false(highlight.has(staticRange));
highlight.add(staticRange);
assert_equals([...highlight.keys()][0], staticRange);
assert_equals([...highlight.values()][0], staticRange);
let callbackCalled = false;
highlight.forEach(() => { callbackCalled = true; });
assert_true(callbackCalled);
}, "Highlight is a setlike interface that works as expected even if Set.prototype is tampered.");
</script>